Before his career in politics, the so-called ‘Beast of Bolsover’ worked as a miner. He’s perhaps more famously, and certainly warmly, remembered as the Labour MP for Bolsover from 1970 until 2019, and this is how he is represented here, as a mature politician. But the colours are reminders that he was no stranger to coal dust and life underground, before his career in the House of Commons.
You can see the picture here: https://www.ncm.org.uk/collections/portrait-of-dennis-skinner/
And you can find out more about Fionn Wilson here: https://fionn-wilson.co.uk/